The present invention relates to shaft components. More particularly, the present invention relates to a safety mechanism for reducing the likelihood of an improper shaft assembly.
Shafts are utilized in many applications and generally require interconnection between the shaft and a secondary component. The secondary component can be an independent component or secondary shafts such that the shaft serves as an intermediate shaft. In both instances, the forward end 22 of the shaft 20 is interconnected with a coupling element 10 which in turn is interconnected with the secondary component (not shown).
Many different coupling elements can be utilized with the present invention, with an exemplary coupling element 10 illustrated in FIG. 1. The coupling element 10 has a shaft receiving and retaining slot 12 and a retaining bolt 16 that is passed through and secured in a through bore 14 in the coupling element 10. Typically, the shaft 20 has a notch, annular groove or other form of bolt receiving recess 24 adjacent the forward end 22 of the shaft 20. The forward end 22 of the shaft 20 is first positioned in the slot 12 (as indicated by the arrow 1 in FIG. 1) with the bolt receiving recess 24 aligned with the through bore 14. Thereafter, the retaining bolt 16 is slid through the through bore 14 and bolt receiving recess 24 (as indicated by the arrow 2 in FIG. 1) and secured by a cotter pin, nut or the like. The retaining bolt 16 extending through the bolt receiving recess 24 permanently secures the shaft 20 to the coupling element 10.
In many applications, for example, a steering intermediate shaft, the interconnection of the shaft 20 and coupling element 10 occurs in a location with limited accessibility. As such, it is difficult to visually or manually check that the retaining bolt 16 is properly received in the bolt receiving recess 24. For example, as illustrated in FIG. 2, the shaft 20 may not be fully inserted into the coupling element slot 12 when the retaining bolt 16 is inserted. As a result, the retaining bolt 16 is not received in the bolt receiving recess 24. In some instances, the forward end 22 of the shaft 20 jams between the inserted retaining bolt 16 and the inner surface 18 of the coupling element slot 12. If the shaft 20 is jammed sufficiently, it may give a rigid feeling to an assembly worker, thereby creating a false sense that the shaft 20 is properly interconnected. After some use, the shaft end 22 may dislodge from between the retaining bolt 16 and slot surface 18, thereby causing disassembly and failure of the coupling.